JP3231953B2 - Power converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter for converting DC power into AC power or AC power into DC power.

[0002]

2. Description of the Related Art FIG. 5 is a diagram showing an example of a main circuit of a conventional uninterruptible power supply. As shown in FIG.
Is connected to one end of an AC reactor 2. The other end of the AC reactor 2 is connected to a three-phase PWM converter 3.
Input side is connected.

The three-phase PWM converter 3 is, for example, an IG
Self-extinguishing type semiconductor device (hereinafter simply referred to as “device”) composed of BT (insulated gate bipolar transistor)
S21 to S26 and diodes D21 to D26 connected in parallel to the respective elements.

The output side of the three-phase PWM converter 3 is connected to a smoothing capacitor 4 in parallel and the input side of a three-phase PWM inverter 5. The three-phase PWM inverter 5 includes, for example, self-extinguishing type semiconductor elements (hereinafter, simply referred to as “elements”) S11 to S16 each formed of an IGBT (insulated gate bipolar transistor) and a diode D11 connected in parallel to each element. To D16.

[0005] The primary side of an inverter transformer 6 is connected to the output side of the three-phase PWM inverter 5, and a filter capacitor 7 and a load 8 are connected to the secondary side of the inverter transformer 6.

FIG. 6 shows a configuration of a control circuit of the three-phase PWM inverter 5. As shown in the figure, the control circuit of the three-phase PWM inverter 5 includes A / D converters 11 to 11 for converting each of the three-phase output voltages (U, V, W phases) to a load into a digital quantity. 13 are provided, and this A /
On the output side of the D converters 11 to 13, the A / D converters 11 to
13 is converted into a common mode component Vd with the power supply voltage.
And an input side of a common coordinate conversion circuit 14 for converting into an orthogonal component Vq.

On the output side of the coordinate conversion circuit 14, a voltage control circuit 15 for performing a control operation such as proportional integration with a difference .epsilon.dv between the voltage command value Vo 'and the voltage Vd of the in-phase component of the power supply after the coordinate conversion is input. Input side is connected.

Similarly, on the output side of the coordinate conversion circuit 14,
An input side of a voltage control circuit 16 for performing a control operation such as a proportional integration is connected to a voltage phase command value '0' and a difference εqv between a power source after the coordinate conversion and a voltage Vq of the orthogonal component as inputs.

On the output sides of the voltage control circuits 15 and 16, the output signals .epsilon.dv and .epsilon.qv from the voltage control circuits 15 and 16 are input, and three-phase load current command signals Iu ', Iv' and Iw.
′ Is connected to the input side of the coordinate conversion circuit 17.

On the output side of the coordinate conversion circuit 17, a digital load current command signal Iu 'from the coordinate conversion circuit 17 is output.
The input sides of D / A converters 18 to 20 for converting Iv 'and Iw' into analog quantities are respectively connected.

The outputs of the D / A converters 18 to 20 receive the differences .epsilon.IU, .epsilon.IV and .epsilon.IW between the analog load current command signals Iu ', Iv' and Iw 'and the three-phase currents Iu, Iv and Iw. , The output signals εIU ′, εIV ′, εI proportional to this input.
The input sides of the current control circuits 21 to 23 for outputting W 'are connected respectively.

Output signals εIU ′, εIV ′, εI of the current control circuits 21 to 23 are provided on the output sides of the current control circuits 21 to 23, respectively.
Gate circuits 25 to 27 that control the inverter elements S11 to S16 are connected based on the comparison result of W 'and the triangular wave Va output from the triangular wave generator 24, respectively.

Next, the operation of the control circuit of the three-phase PWM inverter 5 will be described. First, three-phase output voltages (U, V, W phases) to the load 8 are detected by a voltage detector,
It is converted into a digital quantity by A / D converters 11 to 13.

The converted digital amount of the three-phase output voltage is converted by the coordinate conversion circuit 14 into a power supply voltage in-phase component Vd and a power supply voltage and a quadrature component Vq. Then, a difference signal εdV = V′−Vd between the voltage command value Vo ′ and the voltage Vd after coordinate conversion is input to the voltage control circuit 15,
The proportional integral control operation is performed by the voltage control circuit 15 and εd
It is output as V '.

Similarly, a difference signal εqV = 0−Vq between the voltage phase command value “0” and the voltage Vq after the coordinate conversion is input to the voltage control circuit 16, and the voltage control circuit 16 controls the proportional integration and the like. The operation is performed and output as εqV ′.

The difference output signals .epsilon.dV 'and .epsilon.qV' from the voltage control circuits 15 and 16 are output to a coordinate conversion circuit 17, and the difference output signals .epsilon.dV 'and .epsilon.qV' The current command signals Iu ', Iv',
It is output as Iw '.

Load current command signals Iu ', Iv', Iw '
Are respectively converted into analog quantities by D / A converters 18 to 20 and output. A / D converter 11 described above
To A / D conversion processing of three-phase output voltage by D / A
As shown in FIG. 7, the D / A conversion processing by the converters 18 to 20 is performed by a digital control operation using an interrupt pulse generated every 166 μs.

That is, after the interruption, the A / D conversion processing 31, the proportional integration control operation 32, the sequence control 33, and the D / A conversion processing 34 are performed as described above.
Analog amount load current command signals Iu ', Iv', Iw '
Is output.

The operation delay time td for the above processing is approximately 130 [μs]. The following operation is a three-phase (U,
(U, V, W phases) will be described. The analog current load current command signal Iu output from the D / A converter 18
And the difference εIU = Iu′−Iu between the current control circuit 21 and the U-phase current Iu.

The current control circuit 21 comprises only a proportional amplifier, and outputs an output signal εIU ′ proportional to the input signal εIU. It should be noted that the current control circuit may be added with an integral element or a differential element to optimize the current control system.

The triangular wave generator 24 generates a triangular wave Va having a constant amplitude and a constant frequency, which is a carrier of a so-called PWM inverter.
Occurs. The triangular wave Va and the current control circuit 2
The output signal '1' is output to the gate circuit 25 when εIU '≧ Va, and the output signal' 0 'is output when εIU'<Va.

The gate circuit 25 includes an inverter element S11.
And S14. When the output signal is "1", S11 is turned on and S14 is turned off. When the output signal is "0", S11 is turned off and S11 is turned off.
14 is turned on.

Therefore, the period when the output signal is “1” is “
When the period is greater than 0, the U-phase current IU is increased in the positive direction. When the period of 0 is greater than the period of 1, the U-phase current IU is increased in the negative direction.

That is, the output signal ε of the current control circuit 21
A voltage proportional to IU 'is applied to the load 8. For example, U
When the phase current command value Iu 'is larger than the detection value Iu, εIU = Iu'-Iu becomes a positive value and the output signal εI
U ', that is, the U-phase output voltage Vu is increased.

Therefore, the detected value Iu increases, and finally I
Control is performed so that u = Iu '. Conversely, when the command value Iu 'of the U-phase current becomes smaller than the detection value Iu, εIU
= Iu '-Iu becomes a negative value and decreases the output signal εIU', that is, the U-phase output voltage Vu.

Therefore, the detection value Iu decreases, and finally I
Control is performed so that u = Iu '. Here, the command value I
If u 'is changed in a sinusoidal manner, the detection value Iu is also controlled in a sinusoidal manner following the sinusoidal change.

As in the case of the U-phase current, the load currents Iv and Iw of the V-phase and W-phase also have respective command values Iv ',
It is controlled according to Iw '. Next, a method of controlling the supply current Is from the AC power supply by the three-phase PWM converter will be described.

FIG. 8 shows a configuration of a conventional three-phase PWM converter control circuit. As shown in the figure, this three-phase PWM
The converter control circuit includes an A / D converter 41, a voltage control circuit 42, current control circuits 43 and 44, and coordinate converters 45 and 4.
6, triangular wave generator 47, D / A converters 48 to 50, A /
The D converters 51 to 53 are mainly configured.

The A / D converter 41 converts an analog voltage detection value Vdc into a digital value. The voltage control circuit 42 amplifies or integrates a difference εdc = Vdc′−Vdc between a voltage detection value Vdc converted into a digital amount by the A / D converter 41 and a DC voltage command value Vdc ′ of the smoothing capacitor, and a power supply This is output as the current peak value command Id '.

The A / D converters 51 to 53 are for converting analog power supply currents IR, IS, IT into digital quantities. The coordinate converter 46 includes A / D converters 51-51.
53, the power supply currents IR, I
S and IT are represented by Ids for the in-phase component and Ids for the power supply current and I
Output as qs.

The current control circuit 43 receives a current peak value command Id.
'And the output signal Ids from the coordinate converter 46, εdI =
Id'-Ids is input and amplified. The current control circuit 44 determines the current phase command value “0” and the coordinate converter 46.
ΕqI = 0−Iqs from the output signal Iqs from
A control operation such as proportional integration is performed. Although the current control circuits 43 and 44 are composed of simple proportional amplifiers only, an integral element or a differential element may be added to optimize the current control system.

The coordinate converter 45 includes current control circuits 43 and 4
The outputs .epsilon.dI 'and .epsilon.qI' are output from the three-phase
It is output as R ', Is', IT'. The triangular wave generator 47 generates a triangular wave Vb having a constant amplitude and a constant frequency.

The D / A converters 48 to 50 are coordinate converters 4
5 based on the result of comparison between the power supply current commands IR ', Is', IT' and the triangular wave Va output from the triangular wave generator 47.
An output signal for controlling S26 is output.

In the above configuration, first, the analog detected voltage value Vdc is converted into a digital value by the A / D converter 41 and output. Then, the difference εdc between the voltage detection value Vdc of the digital amount output from the A / D converter 41 and the DC voltage command value Vdc ′ of the smoothing capacitor is εdc = Vdc′−Vdc.
Is input to the voltage control circuit 42, amplified or integrated, and output as the power supply current peak value command Id '.

On the other hand, the analog power supply currents IR, IS,
It is detected and converted into digital quantities by the A / D converters 51 to 53, and the coordinate converter 46 converts the power supply current and the in-phase component into the output signal Ids and the quadrature component into the output signal Iqs and outputs them.

The difference .epsilon.dI = Id'-Ids between the current peak value command Id 'and the output signal Ids from the coordinate converter 46 is input to the current control circuit 43, amplified and output as .epsilon.dI'.

Similarly, after the difference εqI = 0−Iqs between the current phase command value “0” and the output signal Iqs from the coordinate converter 46 is input to the current control circuit 44 and the control operation such as proportional integration is performed. Output as εqI ′.

The coordinate converter 45 includes current control circuits 43 and 4
The output signals .epsilon.dI 'and .epsilon.qI' are converted into three-phase power supply current commands IR ', IS', and IT 'and output. The following operation will be described for the R phase among the three phases (R, S, T phases).

The triangular wave 47 generates a triangular wave Va having a constant amplitude and a constant frequency, which is a carrier of a so-called PWM inverter. The triangular wave Va is compared with the output signal IR 'of the coordinate converter 45, and the output signal' 1 'is output to the gate circuit 48 when IR'≥Va, and the output signal' 0 'is output when IR'<Va.

The gate circuit 48 controls the self-extinguishing type semiconductor power elements S21 and S24 of the converter. When the output signal is "1", S21 is turned on and S24 is turned off. I do.

When the output signal is "0", S21 is turned "off" and S24 is turned "on". Power supply current Is
Is determined by the voltage VL applied to the AC reactor Ls.

The reactor voltage VL is equal to the power supply voltage V
s and the voltage Vdc generated by the three-phase PWM converter. The calculation delay time for the above processing is also approximately 130 [μs] as described above.

[0043]

In the above-described power converter, when the current control circuits 43 and 44 and the voltage control circuits 15 and 16 are constructed by a digital control system, the control responsiveness is reduced by a delay time caused by digital operation. Had the drawback that it became worse.

The present invention has been made in view of the above circumstances, and in order to enhance control responsiveness, a digital control circuit takes out an element which affects the transient response and calculates the part immediately after detecting the part. It is an object of the present invention to provide a power conversion device provided with a circuit for outputting.

[0045]

According to a first aspect of the present invention, there is provided a power converter comprising a plurality of semiconductor elements having a conduction control terminal and supplied from a power supply. A power converter comprising: a converter for converting DC power to AC power or AC power to DC power; and a controller for controlling input of a conduction control terminal of the converter by performing digital control at a constant sampling interval. In the device, a digital converter that converts a power supply voltage into a digital signal voltage, a digital signal voltage output from the digital converter, an in-phase digital voltage signal having an in-phase component with the power supply voltage, and a quadrature component with the power supply voltage A first coordinate conversion circuit for converting the signal into a quadrature digital voltage signal having the same, a common-mode digital voltage signal and a voltage command value signal output from the first coordinate conversion circuit. A first digital proportional amplifier for performing a proportional operation on a first operation output signal indicating the operation result of the above, and an operation result of a quadrature digital voltage signal and a voltage phase command value signal output from the first coordinate conversion circuit The second showing
A second digital proportional amplifier that performs a proportional operation on the operation output signal, a first integration circuit that performs an integration operation on the first operation output signal, and an output from the first integration circuit. A first holding circuit for holding an operation result at the time of the previous conduction control; a second integration circuit for performing an integration operation on the second operation output signal;
A second holding circuit for holding the calculation result at the time of the previous conduction control output from the integration circuit of the above, the calculation result at the time of the previous conduction control held by the first holding circuit, A first digital operation signal obtained by calculating the proportional operation result output from the digital proportional amplifier, the operation result at the time of the previous conduction control held in the second holding circuit, and the second A second coordinate conversion circuit that receives a second digital operation signal obtained by calculating a proportional operation result output from the digital proportional amplifier and outputs a load current digital command signal, and a second coordinate conversion circuit An analog converter that converts the output load current digital command signal to a load current analog command signal for the semiconductor element and outputs the analog signal.

Further, according to the power converter of the second aspect of the present invention, the power converter is constituted by a plurality of semiconductor elements having a conduction control element, and each element is digitally controlled to convert DC power to AC power or AC power to DC power. In a power conversion device that converts power into power at a constant sampling interval, a digital converter that converts a power supply voltage into a digital signal voltage, and a digital signal voltage output from the digital converter is in-phase digital having a component in phase with the power supply voltage. A voltage signal, a first coordinate conversion circuit for converting the power supply voltage into a quadrature digital voltage signal having a quadrature component, and an operation result of the in-phase digital voltage signal and the voltage command value signal output from the first coordinate conversion circuit A first integration circuit for performing an integration operation on a first operation output signal indicating the following, and a quadrature digital signal output from the first coordinate conversion circuit. A second integration circuit that performs an integration operation on a second operation output signal that is an operation result of the voltage signal and the voltage phase command value signal, and an operation result of the first integration circuit and the second integration circuit. A second coordinate conversion circuit that outputs a load current digital command signal by using
A holding circuit for holding the load current digital command signal at the time of the previous current control output from the coordinate conversion circuit of the above, and converting the load current digital command signal held in the holding circuit into a load current analog command signal and outputting An analog converter that outputs a reference value of an output voltage of the power converter, and an analog proportional circuit that proportionally amplifies and outputs a deviation between an output voltage target value output from the reference generation circuit and the power supply voltage. An amplifier, a calculation result at the time of the previous current control output from the analog converter, and a deviation between the output voltage target value output from the reference generation circuit and the power supply voltage, and a load current analog for the semiconductor element. And a circuit for outputting a command signal.

According to the power converter of the third aspect of the present invention, the power converter comprises a plurality of semiconductor elements having a conduction control terminal, and converts DC power supplied from a power supply to AC power or AC power to DC power. And a control unit for controlling the input of the conduction control terminal of the conversion unit by performing digital control at a constant sampling interval. Converter, and a first coordinate conversion circuit for converting a digital signal voltage output from the digital converter into an in-phase digital voltage signal having an in-phase component with a power supply voltage and a quadrature digital voltage signal having a quadrature component with the power supply voltage And a first calculation output signal indicating the calculation result of the in-phase digital voltage signal and the voltage command value signal output from the first coordinate conversion circuit. A first digital proportional amplifier for performing an operation, a first differential operation unit for performing a differential operation on the first operation output signal, a quadrature digital voltage signal output from the coordinate conversion circuit, and a voltage phase command A second digital proportional amplifier that performs a proportional operation on a second operation output signal indicating an operation result of the value signal, a second differential operation unit that performs a differential operation on the second operation output signal,
A first operation for performing an integration operation on the first operation output signal;
An integration circuit, a first holding circuit for holding an operation result at the time of the previous conduction control output from the first integration circuit, and an integration circuit for performing an integration operation on the second difference output signal. A second integration circuit, a second holding circuit for holding an operation result output from the second integration circuit during the previous conduction control, and a previous conduction control held by the first holding circuit. Calculation result at the time and the first
Proportional operation result output from the digital proportional amplifier of
A first digital operation signal obtained by calculating a differential operation result output from the first differential operation unit, an operation result at a previous conduction control held in the second holding circuit, A load current digital command signal is input to a proportional operation result output from a second digital proportional amplifier and a second digital operation signal obtained by calculating a differential operation result output from the second differential operation unit. A second coordinate conversion circuit for outputting the load current digital command signal output from the second coordinate conversion circuit to a load current analog command signal for the semiconductor element, and outputting the analog signal. It is characterized by having.

[0048]

Therefore, first, in the power converter according to the first and second aspects of the present invention, only the proportional operation which affects the transient response is selected and operated. The load current analog command signal is output to the semiconductor device immediately after the operation is performed, and the control responsiveness of the power converter can be enhanced. As a result, a high-performance power converter can be provided. Can be provided.

In the power converter according to the third aspect of the present invention, a differential circuit for performing a differential operation affecting the transient response is further added to the power converter so that not only the proportional control but also the differential control is performed. And a power conversion device with high control responsiveness that can perform the following.

[0050]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A power conversion device according to an embodiment of the present invention will be described below with reference to the drawings. <First Embodiment> FIG. 1 shows a configuration of a three-phase PWM inverter control circuit according to a first embodiment of the present invention. The same parts as those in FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted. Only different parts will be described here.

That is, in the three-phase PWM inverter control circuit according to the first embodiment of the present invention, as shown in FIG.
The input side of a digital proportional amplifier 61 for performing a proportional operation is connected to an output signal .epsilon.dv = Vo'-Vd indicating a difference between the power supply output from the coordinate conversion circuit 14 and the voltage Vd of the in-phase component.

An integration circuit 6 for performing an integration operation
3 and a holding circuit 65 for holding the operation result of the integrating circuit 63
Are connected in parallel with the digital proportional amplifier 61.

On the output side of the digital proportional amplifier 61 and the holding circuit 65, the output of the integrating circuit 63 held in the holding circuit 65 and the coordinate conversion of the signal εdv 'obtained by adding the operation result of the digital proportional amplifier 61 are performed. And the input side of a coordinate conversion circuit 17 for outputting three-phase load current command signals Iu ', Iv', Iw 'is connected.

Similarly, on the output side of the coordinate conversion circuit 14,
An output signal εqv indicating the difference between the voltage phase command value “0” and the voltage Vq of the power supply and the quadrature component output from the coordinate conversion circuit 14
= 0-Vq, the input side of a digital proportional amplifier 62 for performing a proportional operation is connected.

An integration circuit 6 for performing an integration operation
4 and a holding circuit 66 for holding the operation result of the integrating circuit 64
Are connected in parallel with the digital proportional amplifier 62.

On the output side of the digital proportional amplifier 62 and the holding circuit 66, the output of the integrating circuit 64 held in the holding circuit 66 and the coordinate conversion of the signal εqv 'obtained by adding the operation result of the digital proportional amplifier 62 are performed. And the input side of a coordinate conversion circuit 17 for outputting three-phase load current command signals Iu ', Iv', Iw 'is connected.

FIG. 5 shows a digital proportional amplifier 61,
Triangular wave generator 24, showing the positional relationship of the integration circuit 63.
Next, the operation of the three-phase PWM inverter control circuit configured as described above will be described.

First, the three-phase output voltages (U, V, W phases) to the load 8 in FIG.
They are converted into digital quantities by the / D converters 11 to 13. The converted digital amount of the three-phase output voltage is converted by the coordinate conversion circuit 14 into Vd having the same phase component as the power supply voltage and Vq having the quadrature component with the power supply voltage.

The difference output signal .epsilon.dV = V'-Vd between the voltage command value Vo 'and the voltage Vd after coordinate conversion is input to the digital proportional amplifier 61.
, A proportional operation is immediately performed.

Next, an output signal εdv ′ obtained by adding the operation result of the digital proportional amplifier 61 and the output of the integration circuit 63 held in the holding circuit 65 is output to the coordinate conversion circuit 17.

Similarly, a difference output signal εqv = 0−Vq between the voltage phase command value “0” and the voltage Vq after coordinate conversion is input to the digital proportional amplifier 62,
At 2, the proportional operation is immediately performed.

The operation result of the digital proportional amplifier 62 and the integration circuit 64 held in the holding circuit 66
Is output to the coordinate conversion circuit 17.

The subsequent operations of the coordinate conversion circuit 17 and the D / A converters 18 to 20 are as described above. After the end of the D / A conversion processing by the D / A converters 18 to 20, integration operations are performed by the integration circuits 63 and 64 in preparation for the next current control.
This result is held in the holding circuits 65 and 66.

FIG. 2 is a time chart of the three-phase PWM inverter control circuit. A / D converters 11 to 11 described above
13 from the A / D conversion processing of the three-phase output voltage
As shown in FIG. 2, the D / A conversion processing by the converters 18 to 20 is performed by a digital control operation using, for example, an interrupt pulse generated every 166 [μs].

That is, after the interruption, the A / D conversion processing 71, the proportional control calculation, and the addition processing 72 of the result of the proportional control calculation and the output value of the previous integration holding circuit, the D / A
Conversion processing 73 is performed to output analog amount load current command signals Iu ', Iv', Iw '.

After the end of the D / A conversion processing 73, the remaining integral control operation 74 and sequence processing operation 75 are performed. Therefore, from the start of the A / D conversion process, the load current command signal Iu
′, Iv ′, Iw ′ calculation delay time tdf
Can be reduced to, for example, 15 [μs].

As a result, the control responsiveness of the power converter can be improved, and a high-performance power converter can be provided. <Second Embodiment> FIG. 3 shows a configuration of a three-phase PWM inverter control circuit according to a second embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. Only different parts will be described here.

That is, in the three-phase PWM inverter control circuit according to the second embodiment of the present invention, instead of the digital proportional amplifiers 61 and 62, a reference generation circuit 81 for outputting an output voltage target value of the inverter, and Analog proportional amplifiers 82 to 8 for proportionally amplifying the deviation between the output voltage target value of the inverter output from reference generation circuit 81 and the output voltage.
4 is added.

Instead of the holding circuits 65 and 66, holding circuits 85 to 87 for holding the load current digital command signals Iu ', Iv' and Iw 'in the previous current control are connected to the output side of the coordinate conversion circuit 17. I do.

With this configuration, the operation delay time from the start of the A / D conversion processing to the output of the load current digital command signals Iu ', Iv', Iw 'is also made, as in the first embodiment. Can be shortened, and the control gain of the power converter can be improved. Third Embodiment FIG. 4 shows a configuration of a three-phase PWM inverter control circuit according to a third embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. Only different parts will be described here.

That is, in the three-phase PWM inverter control circuit according to the third embodiment of the present invention, in addition to the configuration shown in FIG.
The differential circuit 92 is connected in parallel with the digital proportional amplifier 61.

With this configuration, it is possible to add not only the proportional control but also the differential control that affects the transient response. As a result, the A / D conversion processing is performed in the same manner as in the first embodiment. From the start, the load current command signal Iu ',
The operation delay time until the output of Iv 'and Iw' can be reduced, and the control gain of the power converter can be improved.

In the first to third embodiments described above, the control circuit of the inverter has been described. However, the same method can be applied to the control circuit of the converter.

[0074]

As described above in detail, according to the power converter according to the present invention, the control responsiveness of the power converter is improved by adding the compensation circuit to the power converter constituted by the digital control system. As a result, a high-performance power converter can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a three-phase PWM inverter control circuit according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a time chart of the three-phase PWM inverter control circuit according to the first embodiment.

FIG. 3 is a diagram showing a configuration of a three-phase PWM inverter control circuit according to the second embodiment.

FIG. 4 is a diagram showing a configuration of a three-phase PWM inverter control circuit according to the third embodiment.

FIG. 5 is a diagram showing a configuration of a main circuit of a conventional uninterruptible power supply.

FIG. 6 is a diagram showing a configuration of a control circuit of a conventional three-phase PWM inverter.

FIG. 7 is a diagram showing a time chart of a control circuit of a conventional three-phase PWM inverter.

FIG. 8 is a diagram showing a configuration of a conventional three-phase PWM converter control circuit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... AC power supply, 2 ... AC reactor, 3 ... 3-phase PWM converter, 4 ... Smoothing capacitor, 5 ... 3-phase PWM inverter, 6 ... Inverter transformer, 7 ... Filter capacitor, 8 ... Load, 11-13 ... A / D Converter, 14: coordinate conversion circuit, 15, 16: voltage control circuit, 17: coordinate conversion circuit, 18 to 20: D / A converter, 21 to 23: current control circuit, 24: triangular wave generator, 25 to 27 ... gate circuit, 31 ... A / D conversion processing, 32 ... proportional-integral control calculation,
33 ... sequence control, 34 ... D / A conversion processing, 41 ...
A / D converter, 42: voltage control circuit, 43, 44: current control circuit, 45, 46: coordinate converter, 47: triangular wave generator, 48 to 50: D / A converter, 51 to 53: A / D converter, 61, 62 ... Digital proportional amplifier, 63, 64 ...
Integrating circuit, 65, 66 holding circuit, 71 A / D conversion processing, 72 proportional control calculation and addition processing time, 73 D /
A conversion processing, 74: integration control calculation, 75: sequence processing calculation, 81: reference generation circuit, 82 to 84: analog proportional amplifier, 85 to 87: holding circuit, 91, 92: differentiation circuit.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02M 7/48 G05F 1/10 H02M 7/219

Claims (3)

(57) [Claims] A converter configured to convert a DC power supplied from a power supply into an AC power or an AC power into a DC power; and an input to a conduction control terminal of the converter. And a control unit that controls the digital signal by performing digital control at a fixed sampling interval. A digital converter that converts a power supply voltage into a digital signal voltage in a power converter including: a digital signal output from the digital converter. A first coordinate conversion circuit that converts a voltage into an in-phase digital voltage signal having an in-phase component with the power supply voltage, and a quadrature digital voltage signal having a quadrature component with the power supply voltage; First digital proportional amplification for performing a proportional operation on a first operation output signal indicating the operation result of the in-phase digital voltage signal and the voltage command value signal A second digital proportional amplifier that performs a proportional operation on a second operation output signal indicating the operation result of the quadrature digital voltage signal and the voltage phase command value signal output from the first coordinate conversion circuit; A first operation for performing an integration operation on the first operation output signal;
An integration circuit, a first holding circuit for holding an operation result at the time of the previous conduction control output from the first integration circuit, and an integration circuit for performing an integration operation on the second operation output signal. 2
An integration circuit, a second holding circuit for holding a calculation result output from the second integration circuit at the time of the previous conduction control, and a second holding circuit held by the first holding circuit. , A first digital operation signal obtained by calculating the proportional operation result output from the first digital proportional amplifier, and a first digital operation signal held in the second holding circuit during the previous conduction control. A second calculation result obtained by calculating the calculation result and the proportional calculation result output from the second digital proportional amplifier.
A second coordinate conversion circuit which receives the digital operation signal of the above as an input and outputs a load current digital command signal; and a load current analog command for the semiconductor element which outputs the load current digital command signal output from the second coordinate conversion circuit to the semiconductor element. An analog converter that converts the signal into a signal and outputs the signal. 2. A power conversion device comprising a plurality of semiconductor elements having a conduction control element, and digitally controlling each element to convert DC power to AC power or AC power to DC power at a constant sampling interval. A digital converter for converting a power supply voltage into a digital signal voltage, a digital signal voltage output from the digital converter, an in-phase digital voltage signal having an in-phase component with the power supply voltage, and a quadrature having a quadrature component with the power supply voltage. A first coordinate conversion circuit for converting into a digital voltage signal; and an integration operation on a first operation output signal indicating the operation result of the in-phase digital voltage signal and the voltage command value signal output from the first coordinate conversion circuit A first integration circuit for performing the following operations: calculating a quadrature digital voltage signal and a voltage phase command value signal output from the first coordinate conversion circuit; A second integration circuit that performs an integration operation on a second operation output signal, and outputs a load current digital command signal by using the operation results of the first integration circuit and the second integration circuit as inputs. Second
A coordinate conversion circuit, a holding circuit for holding a load current digital command signal at the time of the previous current control output from the second coordinate conversion circuit, and a load current digital command signal held by the holding circuit. An analog converter that converts and outputs a current analog command signal; a reference generation circuit that outputs an output voltage reference value of the power conversion device; a deviation between the output voltage target value output from the reference generation circuit and the power supply voltage An analog proportional amplifier that proportionally amplifies and outputs a result of the previous current control output from the analog converter, and a deviation between the output voltage target value output from the reference generation circuit and the power supply voltage. And a circuit for outputting a load current analog command signal to the semiconductor element. A converter for converting DC power supplied from a power supply to AC power or AC power to DC power; and an input of a conduction control terminal of the converter. And a control unit that controls the digital signal by performing digital control at a fixed sampling interval. A digital converter that converts a power supply voltage into a digital signal voltage in a power converter including: a digital signal output from the digital converter. A first coordinate conversion circuit for converting a voltage into a common-mode digital voltage signal having a common-mode component with a power supply voltage, and a quadrature digital voltage signal having a quadrature component with the power-supply voltage, and a common-mode output from the first coordinate conversion circuit A first digital proportional amplifier for performing a proportional operation on a first operation output signal indicating an operation result of the digital voltage signal and the voltage command value signal; First performing a differential operation on the first operation output signal
A second digital proportional amplifier that performs a proportional operation on a second operation output signal indicating the operation result of the orthogonal digital voltage signal and the voltage phase command value signal output from the coordinate conversion circuit; A second operation for performing a differential operation on the second operation output signal;
A first arithmetic unit for performing an integration operation on the first operation output signal
An integration circuit, a first holding circuit for holding an operation result at the time of the previous conduction control output from the first integration circuit, and a second operation for performing an integration operation on the second difference output signal. 2
An integration circuit, a second holding circuit for holding a calculation result output from the second integration circuit at the time of the previous conduction control, and a second holding circuit held by the first holding circuit. , A proportional operation result output from the first digital proportional amplifier, a first digital operation signal obtained by calculating a differential operation result output from the first differential operation unit, and A calculation result at the time of the previous conduction control held in the second holding circuit, a proportional calculation result output from the second digital proportional amplifier, and a differential calculation result output from the second differential calculator A second coordinate conversion circuit that receives a second digital calculation signal obtained by calculating the second coordinate conversion circuit and outputs it as a load current digital command signal; and a load current digital circuit that is output from the second coordinate conversion circuit. Power conversion apparatus characterized by comprising an analog converter for converting the Le command signal to the load current analog command signal to the semiconductor element.